Conventional lipstick products typically comprise pigments and oils dispersed in a wax base. The wax base serves to provide the necessary stiffness and physical stability so that the composition can be in the form of a self-supporting stick desired by consumers. However, as a consequence of the high wax levels typically required to achieve these characteristics, conventional lipsticks suffer several disadvantages. Notably, they do not deliver a high gloss finish, are readily transferred from the lips to clothing, napkins, cups and the like, and exhibit undesirable bleeding of the pigments and oils from the product (syneresis). Recent approaches to overcoming some of the disadvantages of waxy lipsticks have centered primarily on the use of polymeric film formers in addition to, or as a partial replacement for, conventional waxy components in order to provide more robust films that are less prone to transfer and longer wearing. However, such products have heretofore not been able to achieve a high gloss, primarily because the opaque waxes dull the finish. Further, the wax structure of conventional lipsticks is known to break down under shear encountered during normal wear and rapidly lose the unctuous feeling of freshly applied product.
So-called “lip gloss” products are also known which deliver a glossy finish and maintain a satisfactory oily rheology during wear but are not durable and must be frequently reapplied to the lips to maintain the desired finish. Lip gloss products are typically transparent or translucent oil-based formulations which may also comprise low levels of colorant. High shine lip glosses are usually high viscosity liquids and therefore cannot be delivered in the convenient form of a self supporting stick but rather are packaged in tubes, pots, and the like and are typically applied to the lips with the fingers or an applicator.
There is a continuing need in the art for lip products, particularly lipsticks and lip glosses that overcome one or more of the foregoing deficiencies of conventional lip products. It would be desirable to combine the convenience and deep color of a lipstick with the high gloss and desirable rheology of a lip gloss to provide lip products, particularly pigmented lip products in stick form, which provide superior gloss, slip, feel, payoff, and/or wear. It is therefore an object of the invention to provide lip products in stick form which deliver a high gloss. It is yet another object of the invention to provide low-wax content lip products having a hardness sufficient for forming a self-supporting stick. It is a further object of the invention to provide lip products in stick form which have a rheology characterized by an unctuous feel which does not diminish during wear.